Fluid amplifier controlled respirator



April 23, 1968 H. zlERMNN 3,379,194

FLUID AMPLIFIER CONTROLLED RESPIRATOR Filed June 29, 1965 4 sheets-sheet 1 April 23, 1,968 H. ZIERMANN 3,379,194

FLUID AMPLIPIER CGNTHOLLED RESPIRATOR Filed June 29, 1965 4 Sheets-Sheet -2 F/QZ April 23, 1968 H. ZIERMANN 3,379,194

FLUID AMPLIFIER COYTROLLED RESPIRATOR Filed June 29, 1965 4 Sheets-Sheei :5

April 23, 1968 H. ZIE-RMANN 3,379,194

FLUID AMPLIFIER CONTROLLED. RESPIRATR` Filed June 29, 1965 4 Sheets-Sheet 4 r States Patent trice savais Patented Apr. 23, i958 3,379,194 Fili@ AMPLIFIER CNTRLJEE RESPERATR Hermann Zierrnann, Cheshire, Coun., assigner to United A rcraft Corporation, East Hartl-ord, Conn., a corporatron of Balai/vare Filed .lune 29, i965, Ser. No. 467,838 it) Claims. (Ci. iwi) ABSTRACT THE DESCLSURS A pure uid amplier aulgments or controls respiration and includes feedback passages and restrictions for controlling the inspiration to expiration ratio, the shape of the pressure curves and the negative pressure. A nebulizer is incorporated in combination with the amplifier in a manner to prevent the loss of medication in the expiration cycle.

This invention relates to respirators of the types that can assist or control respiration utilizing pure lfluid ampliers.

As is generally Well known in the art the respirator is a device intended to assist a patient, generally, one allicted by certain pulmonary diseases, in breathing. In some applications this device may be employed as a respirator which provides an assist to the patient so that relatively little effort on the part of the patient is required to effectuate breathing, and in others it can be employed as 'a resuscitator to provide positive breathing. While there are presently a number oi respiratory devices availabe, these devices are characterized as being very costly and/or operate by a very high pressure which are occasioned by the fact that they require a number of moving parts such as valves operated by diaphragms and bellows. The complexity of the respirator which obviously materially affects the cost thereof can be reduced by utilizing a pure iluid amplifier which switches without the use of any moving parts the liuid from a source of pressure to supply a certain predetermined volume oi huid during the inhalation cycle and then utilizing the pressure from the source to assist during the exhalation cycle. in such a device the patients breathing etlort is significantly reduced and hence, requires substantially little effort to provide the switching from the inhalation to the exhalation cycles. In this type of respirator it is possible to provide up to 90 liters per minute of air with as little as 2 4 psi. at the power nozzle of the fluid amplier.

One of the problems attendant the respirator is the application of ya nebulizer which is intended to supply to the patient a line mist of medication which is adapted to be injected into the lungs for breaking down the congestion therein. A nebulizer to be effective must be positive and must be intermittent so that it is only operable during the inhalation cycle and inoperable during the exhalation cycle. If the nebulizer is operated during the expiration cycle, the medication iluid is then rejected out of the system without any beneiit to the patient and, hence, is considered a mere less in the system. Generally, nebuiizers, per se, which `are well known in the art require a considerable amount of pressure to atomize the medication which pressure is customarily supplied through a separate connection. I have found that I can use a nebulizer with a capillary tube injected into Certain locations in the amplifier which will supply positive intermittent nebulization (during the inhalation cycle only) while eliminating a separate extra fluid connection for driving the nebulizer. Again, this affords simplicity in the respirator system while reducing the cost thereof.

As is generally well known in the art a uid amplifier is basically a device in which lan input or power fluid tlow is modulated between two or more output channels by the application of a control Huid stream generally disposed at right angles to the power fluid ilow at the inter-action section of the lluid amplier. There are two basic types of uid ampliers, namely, proportional and digital. This application is directed to the utilization of the digital type of pure iluid amplier, i.e., Where the power stream adheres to one of the output channels until a control signal causes a switchover. For a general description of pure fiuid amplifiers reference should be made to US. Patent No. 3,122,165, issued to B. M. Horton.

In the use of uid amplifiers it is pointed out here that certain dimensions become critical so that the switching from one channel during inhalation to the other channel during exhalation takes place upon reaching a redescribed pressure in the mouthpiece and the transition from the inhalation to exhalation and back to inhalation must be smooth and gradual.

ln addition to the requirements noted above, the respirator must, whether for home or clinical use, be able to supply variable volumes of air inasmuch as lung capacities of diierent patients vary. As noted above, the type of respirator constituting the present invention operates at a substantially low pressure in comparison to the prior art respirators. There are two ways in which the volume can be altered, one is by supplying more air to the input of the iluid amplifier by increasine the output of the compressor or source of pressurized air and second, to provide additional ilow by controlling the output of the amplilier. In either situation care must lbe taken to assure that the pressure in the mouthpiece or that which enters into the lungs does not exceed an intolerable level which may result in injury to the patient. Two flow controls may be provided such that one of the controls has a varying pressure and the other varies the ow without a pressure change. By the use of one of the flow controls as long as the pressure is sutlicient to switch from inhalation to exhalation and vice versa, the patient can vary the flow without a pressure change.

As was mentioned above the respirator must assure that the pressure in the mouthpiece or that which enters into the lungs does not suddenly increase or decrease but rather goes through a smooth transitional change without imposing injury or discomfort to the user. It has been found that this smooth transition can be accomplished by closely controlling the lgeometry of the inner action region and also by providing in the feedback loop of the fluid amplier a positive pressure control and in another feedback loop a negative pressure control interconnecting an outlet passage communicating to ambient. These controls are manually adjusted to set an area in these feedback passages and serve to provide a smooth and gradual from inhalation to exhalation and vice versa.

A feedback loop is also provided in the exile-.lation passage and a manual control is inserted therein which serves to adjust the ratio of inhalation to exhalation cycles. As an assist type cr respirator it is noted that the actual control of the inhalation and exhalation cycle is done by the patient by his own impetus in breathing. ri`he respirator is set for a predetermined ratio of exhalation to inhalation. However, the impetus of the switching ocy curred by the breathinfVT of the patient overrides this ratio but since the fluid amplilier is set for a natural or normal ratio, a little additional effort is required by the patient to overcome this natural setting. However, once the breather becomes accustomed to the respirator with the set inhalation to exhalation ratio he will eventually come into rhythm with this setting.

In the inner region of the fluid amplifier, a double feedback loop may be utilized to bias the control port with the flow in the inlet or outlet output channels for reducing the patients effort necessary to effectuate switching from the inhalation to exhalation cycles.

The respirator must also assure that during the inhalation cycle the flow can be regulated without a pressure change and the pressure can be regulated without a flow change, and also during the exhalation cycle excessive ambient air must not be induced in the inhalation passage. This is accomplished by the particular flow control and fluid diode valve -disclosed in this application. As will lbe described in more detail hereinbelow, the diode valve is judiciously inserted in the fluid amplifier and serves to decouple the output load (mouthpiece) and the iner action region of the amplifier during the inhalation cycle. In this manner the flow control valve inserted in the fluid amplifier is utilized to adjust the flow to the patients lungs yet without changing the mouthpiece pressure at which the fluid amplifier switches from inhalation to exhalation. Also a manual positive pressure control in the feedback loop can be utilized to adjust the swiching pressure without affecting the flow.

It is therefore an object of this invention to provide a respirator that is characterized as having no moving parts, highly reliable, can be employed as a clinical or portable home unit, is simple to manufacture and economical to build. Such a respirator is also characterized by the fact that its operation is relatively simple so that the patient can use it without the assistance of a technician or medical doctor. It is also characterized by the fact that it operates at a very substantially low pressure so that in the event of a malfunction the pressure is not sufficient to cause injury to the patients lungs.

A still further object of this invention is to provide in a respirator as described an intermittent and positive nebulizer uniquely combined with a fluid amplifier so that fluid medication in the nebulizer is not rejected in the exhalation cycle.

A still further object is to provide suitable feedback means for assuring that there is a smooth transition from the exhalation to inhalation and back to the exhalation cycles.

A still further object of this invention is to provide in breathing apparatus means for changing the unit to either an assist or control type of respirator by a mere `setting of a valve.

A still lfurther object of this invention is to provide additional feedback means to reduce the patients efforts in switching from the inhalation to the exhalation cycles.

Other features and advantages will be apparent from the specification and claims and from the accompanying drawings which illustrate an embodiment of the invention.

FIGURE l is a perspective view of the entire respirator as packaged as a portable unit.

FIGURE 2 is an exploded perspective view of the amplifier and its varous controls.

FIGURE 3 is an elevated view of the diode valve.

FIGURE 4 is a sectional view taken along lines 4 4 of FIG. 3.

FIGURE 5 is a schematic illustration of the pure fluid amplifier utilizing an ejector.

FIGURE 6 is a partial end view of FIG. 5 illustrating the controllable bleed valve in the ejector.

FIGURE 7 is a view in elevation illustrating the flow inducer section.

FIGURE 8 is a sectional view taken along lines 8 3 of FIG. 7.

FIG. 9 is a sectional view of the nebulizer of the type illustrated in FIG. l.

FIGURE 10 is a schematic view partly showing the fluid amplifier and particularly illustrating judicious location for placing the neublizer. f

FIGURE 11 is a sectional View taken along lines lit-11 of FIG. 10.

Referring now more particularly to the details of this invention as is illustrated in FIG. l, the respirator comprises basically a compressor generally illustrated by numoral 10, the fluid amplifier generally illustrated by numeral 12, the mouthpiece I4 and a nebulizer 16 inserted between the mouthpiece and the amplifier 12. Compressors that are currently available inherently produce a pressure pulsation in the discharge flow which may be eliminated by incorporating an accumulator which is illustrated by numeral 18. The accumulator is merely a plenum chamber that is inserted between the fluid amplifier and the discharge end of the compressor. Suitable valving may be utilized to control the flow from the accumulator to the fluid amplifier. Fluid from the compressor is fed to the accumulator through line 20 and is directed to the fluid amplifier through piping 22 which is helically wound so as to reject the heat picked up as a result of compression. A flexible cable 24 may be utilized to interconect line 2) to the fluid amplifier af fording freedom of movement of the mouthpiece. .A bleed line 26 is tapped into line 2G at the discharge end of the compressor for supplying a pressurized fluid to nebulizer 16.

The unit may also contain a visual pressure gauge of any suitable type generally indicated by numeral 28 which is connected to fluid amplifier l2 in such a way as to allow the patient to visually inspect the pressure of the fluid entering into the mouthpiece 14.

It will be appreciated that mouthpiece 14 is detachable from the unit so that a suitable face mask may be utilized in its place. The compressor and accumlator and cooling coils are encapsulated in a suitable housing 3i) which, in turn, is mounted in a portable suitcase generally indicated by numeral 32. This, of course, illustrates the simplicity of the unit while also pointing out that such a unit is portable.

Looking now at FIG. 2 the details of the fluid amplifier will next be described. This fluid amplifier may be formed into two plates which may be made from suitable t plastic material. The cover plate 36 may be secured by any suitable well-known means to overlie the top surface of plate 38. Fluid from the compressor 10 is admitted to the power nozzle 40 through line 24. From there the flow enters the inner chamber 42 of fluid amplifier 12 I Where it can be directed to either the channel 44 formed on the left of splitter 46 or channel 48 formed on the right side of splitter 46. The flow passing through channel 48 is eventually directed to the mouthpiece and for the purposes of this description will be hereinafter referred to as the inhalation channel. Looking for the moment at the operation during the inhalation cycle, the flow entering the inner chamber normally will adhere to the right wall to the inner chamber and flow onward through the inhalation channel to the mouthpiece. Channel Sil communicating at the upper end of channel 48 senses the pressure therein which is obviously at the same value as the t pressure in the mouthpiece, Where it is directed to discharge in the main stream of the inner chamber adjacent the power jet and serves to create a pressure differential thcreacross. This is known in the art as the control channel and it may be locatedso that the flow from the coutrol channel will be relative to the flow in the inner chamber. When the pressure in the feedback channel 56 reaches a predetermined value, the flow in the inner chamber locked-on to the right-hand wall will be caused to switch to the left-hand wall to flow through the left-` hand channel 44 hereinafter referred to as the exhalation channel. An enlarged chamber 44 is formed in the upper portion thereof and is adapted to communicate with bleed valve 52 secured in position in a recess 54 formed in the top plate. A plurality of holes 56 formed in the top cover of bleed valve 52 bleed air to ambient at a given back pressure level.

In order to control the flow in the inhalation channel without effecting a pressure change, diode valve 58 judiciously located adjacent the inhalation channel is mounted in the top plate and contains an opening located at the bottom end thereof which is in communication with the opening 6@ adjacent the inhalation channel. A portion of the flow in the inhalation channel, therefore, will pass through opening dll into chamber 6?. into the inner cylindrical opening in fluid diode S8, pass through the leg por tion 64 of diode 58 and then out to ambient through the opening formed on the top of leg portion 64.

For the moment referring now particularly to FIGS. 3 and 4 which show the details of the fluid diode (like reference numeral reference like parts). The fluid diode is substantially an enclosed cylinder having a leg depending tangential to the outer wall. The diode is enclosed by a suitable wall 66 defining a cylindrical cavity 68 and a rectangular cavity 78. Gpening 72 formed on the bottom wall communicates with the inner cylindrical cavity 6-8 which cavity in turn communicates with cavity '7u from where flow is directed to ambient through opening 74. As will be apparent, iiuid in the fluid diode valve ows in both directions, namely, into opening '7d through cavities 7l) and 68 and then out through opening 72 and vice versa. Owing to the fact that the flow entering opening 7d is directed tangentially and then swirls to form a vortex in cavity 68 before discharging through aperture 72, a greater resistance will be evidence than when the flow enters 72 and passes through opening 7d. Hence, it is apparent from the foregoing that the ilow entering through '72 and discharging through 7d under the same pressure conditions will afford less resistance than relative to the flow entering 'ifi and discharging through 72. The iluid diode, thus, decouples the airstream downstream thereof (inner action region) and the airstream just upstream thereof (mouthpiece) during the inhalation cycle. Fluid is bled to ambient through the fluid diode at a rate dependent on the setting of valve 76. Low settings will provide high leak rates and high settings will provide low leak rates tending to maintain the pressure in the system at a constant value. The fluid diode during the exhalation cycle restricts the admittance of ambient air so that no interference with the switching will occur.

Referring back to FlG. 2 flow valve 76 inserted through opening 78 formed on the top plate contains a portion Sil partially circular in cross section which projects into recess S2 formed adjacent the inhalation channel 4S. Rotation of 75 serves to vary the area of the inhalation channel just upstream of the mouthpiece. Flow valve 76 working in conjunction with fluid diode 6d allows the patient to adjust the flow from say 50 liters per minute (1./m.) to 90 1./rn. and increments therebetween without changing the pressure necessary to effecuate switching.

Considering next the expiration cycle which occurs when the pressure in the mouthpiece, as will be evidenced in the inhalation channel 43 downstream of recess 32, reaches a predetermined value. This pressure fed back through feedback channel creates an unbalanced force across the main stream and causes it to switch from the inhalation channel to the exhalation channel. The flow, diverted to channel 42 passes into cavity i4 where it is bled to ambient through openings Se in the bleed valve 52 and through passage S3. As will be observed from FlG. 2, the flow adjacent the edge of the splitter o entering channel 42 effectively induces fluid out of channel d3 and the flow in channel 83 likewise induces fluid out of channel 48 through channel 84, having the overall effect of inducing the flow at a quick and fast rate out of the lungs while the patient is exhaling without the necessity of providing a movable type of exhalation valve.

As noted, pressure in chamber 44 is fed to control port 3? via feedback channel Sti and when it reaches a predetermined value, an unbalance of force across the main stream is created causing the stream to switch back to the inhalation channel.

From the foregoing it is therefore apparent that the control feedback channels Si) and 86 effectively change the pressure differential across the main stream causing the stream to switch from the inhalation to the exhalation cycle and vice versa. The rate of change of the inhalation to eXhalation ratio (I/E) is controlled by the proper sizing of openings 56 and the setting of the manual adjustable valve 88 which is rotatably supported in opening 9) formed in the cover plate 36 and the registering recess 92 formed in the bottom plate 38. The slot M of valve stern 8f cooperates with feedback channel S6 to meter the ilow to control port `t' and the rate of tiow therethrough adjusts the I/E ratio. Adjustment of valve 88 also controls, the sensitivity from a positive pressure level to a negative pressure level. By virtue of this control the unit can be utilized as an assist or control type of respirator and including the intermittent positive pressure breathing ap paratus. That is to say, by changing the setting of valve 8S, the pressure in the mouthpiece can 'be adjusted to a peak pressure and any intermediate pressure for a given l/E cycle. Thus, for example, as an intermittent positive pressure type, the pressure in the mouthpiece will range between l0 and 30 centimeters of water. As an assist type of respirator, the pressure in the mouthpiece will normally range between 0 and 30 centimeters of water.

As can be seen from FIG. 2, feedback channel is provided and connected to ambient for the purpose of controlling the sensitivity of the fluid amplifier. A manually adjustable valve 96, similar to valve S8, is inserted into recess 98 adjacent the line illu for controlling the sensitivity of the fluid ampliiier. Valve 96 can be adjusted to create a negative pressure in the face mask if so desire Valve 102, similar to valve 38, fits into recess 164 adjacent feedback line Se for adjusting the flow to control port Si. Proper balancing of the settings of valves 96 and F2 will assure a smooth and gradual transition in the switching from the inhalation to exhalation and exhalation back to inhalation cycles.

It is also possible to reduce the patients efforts in switching from the inhalationcxhalation cycles by providing an additional pair of feedback channels 165 and i136. Both feedback channels 165 and litt? communicate with the main flow in the inner chamber at a point approximately in line with the edge of splitter o so as to bias the control ports 87 and 51.

Channel 108 communicates with the pressure in the inhalation channel and connects with gauge 2.@ via conduit 106.

in certain applications, when the llow control valve 76 is set for minimum flow, it is pos-sible that the switching will occur prematurely. This premature switching may be prevented by incorporating a iluid diode S2' similar to, but having lower flow characteristics than, fluid diode 53. rhis iluid diode will serve to decouple the main stream just downstream of valve 76 from the stream upstream of valve '76 during the exhalation cycle.

Still referring to FlG. 2, it will be noted that th width of channels 48 and S3 are wider at the point just downstream or" the passage Sd. Walls d and 83' are stepped inwardly relative to the channels so that when the main stream is flowing through the respective channels and $3 a negative pressure region will be created adjacent the recessed walls, This effectively induces flow from one channel to the other to increase the volume of flow to the lungs in the inhalation cycle and increase the volume of flow discharging out of the lungs in the exhalation cycle. Hence, it will be apparent that during the inhalation cycle, flow passing through channel 48 adjacent wall 43', creates a low pressure region which creates a pressure drop across the ends of channel S4. As a result, ilow will be induced from ambient via bleed valve 52. and channel S3.

During the exhalation cycle the main stream being divertedto the left of splitter 45 passes through channel i2 and then through 83. Similarly, adjacent the recessed wall 23 a negative pressure will be created and a pressure drop will `be evidenced across channel 4. This will induce low out of channel 48 when the breather is exhaling.

A respiratory unit as the one described above has proven to be eicacious with the following dimensions of the i'luid amplifier. It is to be understood, however, that the example below is included herein for illustration purposes and is not to be construed as limiting the scope of the invention.

Splitter location So that unit is a memory device.

Aspect ratio Not smaller than 4 to l,

Power nozzle width Between .030 and .050

inch.

Inside Diameter' Diameter 72 Width of T0 oit Diode 58, i11. .400 .15G .060 Diode 58', i11.. .40() .15G .032

While the amplifiers which have already been successfully tested were formed from plastic material, namely, acrylic type polymer and polycarbonate, it is to be understood that it is within the scope of this invention to use any other material whether it be metallic or nonmetallic. However, it should be understood that the material selected must be capable of withstanding autoclaving.

The unit described above has not only been successfully employed to sustain respiration in open-chest surgery of dogs, it has also been successfully used by human patients afflicted with emphysema.

As noted in the description of FIG. 2, additional tiuid is induced into the mouthpiece by providing certain passages communicating with ambient and constructing those passages in a particular manner. The description to follow in connection with FiGS. 5-7 are means for inducing the iiow by incorporating an ejector pump which pump is suitably controlled by mechanical means for controlling the ow through the mouthpiece. The iluid amplier portion is similar to the one disclosed and described in connection with FIG. 2 but may include in the various passages divided by a splitter, a bucket for providing smoother flow in the reverse direction. The iiuid amplifier similar to the one described in FIG. 2 is comprised of a power nozzle 200 which directs iluid to either inhalation channel 202 and alternately to discharge or exhalation channel 204. Feedbacks connected to the inner action region 206 are provided and serve the same purpose as was described in connection with FIG. 2. A positive pressure control 208 and negative pressure control 210 are provided `and again serve the same purpose. As noted, however, in connection with FIG. 2, the channels were all rectangularly shaped in cross section. However, the shape of the ejector passages are circular in cross section rather than being rectangular. The ejector section 212 may be secured in any suitable means, such as bonding, to the amplification section 214 and contains the main tiow passage 216 registering with the inhalation passage 202. This passage flares out to a wider dia-meter at the discharge end 218 so that the uid adjacent the fluid amplifier passes through a restricted area or a throat section of the ejector. Disposed at the throat is a passage 220 which communicates with ambient through the passage 222 formed in the rotatable plate 224. `A plurality of openings 226 are provided to communicate with annular chamber 228 communicating with passage 220. Thus, the high speed liow passing through the throat section 216 induces ythe ow through passages 220 and 222 and carries it to the mouthpiece (not shown) through the outlet 218. Thus, during the inhalation cycle additional iiow is induced into the mouthpiece without the need of a larger pump. The amount ot additional tiow induced through the ejector is controlled by the rotatable plate 224 which carries opening 222 communicating with the opening 220 and thus defining the area exposed to ambient. Plate 222 is rotatably mounted adjacent the side wall of the combined ejector and uid amplifier sections and may be retained in position for rotatable movement by any type of rod illustarted by screw arrangement 230.

In the exhalation cycle the ow entering into the opening 218 and discharging from the patients lun-gs will discharge overboard to ambient through passages 232 and 234 and will be induced therefrom at the faster rate by virtue of the fact that the flow from the power jet nozzle 200 passes into expiration channel 204 and out of chamber 236 to ambient and then through passage 234. The high stream flow induces iiow out of passage 216.`

Looking at FIG. 7 for the moment, the ejector may be made into a separate part that tits in a cylindrically shaped recess 240 and is comprised of a cylindrical body 242 which contains the diverging passage 21.6 and the annular groove 21S communicating with the feedback line 244 and the pressure sensing line 246. Passage 232 communicates with the main stream ofthe ejector through the passage 248 which registers with passage 232.

Thus it is apparent from the foregoing that the ejector serves to assist the patient in his breathing both during the inhalation and exhalation cycles.

As was mentioned above, it is necessary in many respirator applications to provide medication to the patients lungs which may be accomplished by incorporating a suitable nebulizer. FIG. 9 illustrates the nebulizer that uses the aspirator principle for inducing uid into the main stream during the inhalation cycle and provides means for preventing the medication to be carried over and vented during the exhalation cycle. Looking at the details of FIG. 9 it can be seen that a nebulizer bottle 260 containing suitable medication is threadably secured to the nebulizer section 16 by the internally threaded tiange 262 which receives the external thread formed on bottle 260. A tube 264 projecting into the bottle terminates adjacent tube 286 connected to `the discharge end of accumulator 18 by the T connection 268. The angle of the tube 286 relative to the tube 286 is oriented so that it denes an angle of no less than 72. A deliector plate 270 having a beveled end 272 is spaced in such a way that .the dow discharging from pipe 286 impinges on the beveled face 27.2 which is spaced approximately 250 inch downstream therefrom. This serves to deflect and break up heavy particles which leave tube 264. The fine particles which are sheared and deflected in an upward direction owing to the shape of the end of plate 270 discharge into the main stream flowing t0 the mouthpiece during the inhalation cycle. Plate 270 is supported in position by any suitable means to wall 274.An opening 276 formed in wall 274 communicates with the reservoir 278 formed in container 260. This serves to collect the excess particles which are not picked up in the .main stream during the inhalation cycle.

It will be noted that the opening 280 which connects to the mouthpiece is lower than the opening 282 which connects to the fluid amplilier. `This serves to prevent the medication uid from being carried back through the iiuid amplitier and discharged overboard during the exhalation cycle. Thus, during the exhalation cycle the air tiowing` back through opening 280 will carry any fluid contained in the stream to impinge on the back wall 284 of .the`

nebulizer and the back face of plate 270. Additionally, the ow passing over the plate 270 prevents particles from bein-g sheared oi and deflected to the main stream and also serves to provide turbulence so as to prevent nebulization.

Nebulization can `also be achieved by providing mechanism that may be attached directly to the uid amplier.

This is iilustrated by drawings depicted in FIGS. l0 and 1l wherein FIG. 10 schematically illustrates the fluid amplifier showing the power nozzle 300, the inner action region 302, the inhalation channel 304 and exhalation channel As is understood by those skilled in the art, when the flow discharging from the power jet (illustrated by lines Stad) liow adjacent one wall, it creates a low pressure region known as a bubble. By inserting a capillary tube in the bubble, which capillary tube communicates with the medication as can be seen in FIG. 1l during the inhalation cycle, the low pressure region will induce the medication from reservoir 31) and aspirare it into the inner action region of the fluid amplier where it is picked up and carried to the mouthpiece through channel 304i. Since the bubble will be located adjacent the opposite wall of the inner action region during exhalation cycle, there will be no nebulization.

It has also been found that the end of the capillary tube 312 may be located adjacent the end of the inner action region in the center of the inhalation channel Still. Another suitable location for the capillary tube 312 is directly in the channel 3nd but in close proximity to its discharge end. With respect to the latter two mentioned locations when the respirator is in the reverse flow, that is during the exhalation cycle, the liow over the capillary tube is so slow that no fluid pickup is possible and therefore interrni ent nebulization as assured. The nebulizer bottle may be suitably threaded to recess 314 formed in the wall of the nebulizer. Pressure is bled internally of the container 3io through openings Siti for forcing the medication through the capillary tube 312.

it should be understood that the invention is not limited to the particular embodiments shown and described herein but that various changes modifications may be made without departing from the spirit or scope of this novel concept as defined by the following claims.

l claim:

i. A respirator of the type that controls or assists in respiration including in a source of fluid under pressure, a pure fluid ampli-lier, a mouthpiece and conduit means interconnecting said source, said pure fluid amplifier and said mouthpiece, said pure fluid amplifier includinfy a body having a power nozzle, V-shaped passage connected thereto by an inner action region and the apex of said V-sliaped passage defining a splitter, the first leg of said V-sliaped passage connected to said mouthpiece, first passage means including c. first control port angularly disposed relative to the inner action region for leading fluid thereto from one leg of said V-shaped passage for switching the fluid issuing from said power nozzle from one leg to the other leg of said 'if-shaped passage, second passage means including a second control port angularly disposed relative to said inner action region leading fluid thereto from the other leg for switching the fluid issuing from said power nozzle from said other leg to said one leg of said V-shaped passage, the improvement comprising third passage means in said body interconnecting ambient and said second control port and adjustable valve means disposed in said first, second and third passage means.

2. A respirator as claimed in claim l including restriction means disposed in said second passage means communicating with ambient.

3. A respirator as claimed in claim 2 wherein said restriction means includes a hollow cylindrical member mounted in a complementary opening formed in said body and a top plate having a plurality of openings formed therein.

A respirator as claimed in claim i including nebulizing means, said nebulizing means including a container for holding liquid medication mounted adjacent to but external of said body, a capillary tube extending internally in said container and projecting in the inner action region adjacent the wall of said first leg where the bubble forms, and openings in said body interconnecting said inner action region and said container.

5. A respirator as claimed in claim i including nebulizmeans, said nebuilizing means including a container for holding liquid medication mounted adjacent to but external of said body, a capillary tube extending internally in said container and projecting in said lirst leg adjacent said splitter, and openings in said body interconnecting said iirst leg and said container.

6. A respirator as claimed in claim ll including nebulizing means, said nebulizing means including a nebulizirig section in said conduit means intermediate said mouthpiece and said pure fluid amplifier, a container housing liquid medication mounted adjacent said nebulizing section, inlet and outlet ports in said nebulizing section being axially disposed relative to each other but having the outlet port being lower than the inlet port, a first tube extending from said container into said nebulizing section adjacent to but below the inlet port, a second tube also extending into said nebulizing section having its end terminating adjacent the end of said first tube and disposed at an angle of no less than 72 relative to said first tube, a fiat plate having a beveled face extending into said neubulizing section, and passage means interconnecting said second tube and said source, such that the fluid issuing from said second tube impinges on said beveled face.

7, A respirator adapted to control or assist in respiration of the type that includes, a source of fiuid under pressure, a pure tluid amplifier, said pure fluid amplifier including a body having a power nozzle, and V-shaped passage connected thereto by an inner action region, a mouthpiece and conduit means interconnecting said source, one leg of said V-shaped passage orf said pure fluid amplifier and said mouthpiece, first feedback means for switching the fluid issuing from said power nozzle to one leg or the other leg of said il-shaped passages, said feedback means including .a first control port angularly disposed relative to the inner action region for leading fluid downstream of said inner action region thereto from one leg of said V-shaped passage, and a second control port aiigularly disposed relative to said inner action rogion leading fluid downstream of said inner action region thereto from the other leg, the improvement cornprising second feedback means including passages formed in said body for leading iiuid from said inner action region to said first and second control ports.

8. A respirator adapted to control or assist in respiration comprising, in combination, a source of fluid under pressure, a pure fluid amplifier, a mouthpiece and conduit means interconnecting said source, said pure fluid amplifier and said mouthpiece, said pure fluid amplifier including a body having a power nozzle, V-shaped passage connected thereto by an inner action region, the first leg of said V-sliaped passage connected to said mouthpiece, first passage means including a first control port angularly disposed relative to the inner action region for leading iiuid thereto from one leg of said V-sliaped passage for switching the fluid issuing from said power nozzle fiom one leg to the other leg of said if-shaped passage, second passage means including a second control port angularly disposed relative to said inner action region leading fluid thereto from the other leg for switching th fluid issuing from said power nozzle from said other leg to said one leg of said V-shaped passage, the improvement including third passage `means in sai-:l body interconnecting arnbient and said second control port, adjustable valve means disposed in said first, second and third passage means, restriction means disposed in said second passage means communicating with ambient, a fourth passage means interconnecting said restriction means and ambient and a ifth passage means interconnecting said fourth passage means and first leg.

9. A respirator as claimed in claim 8 wherein said first leg and said fourth passage means are defined by parallelly spaced wall means, the distance between opposing parallel walls being increased for a predetermined length extending from said fifth passage means to the edge ctf said bodv.

it?. A respirator adapted to control or assist in respiration comprising, in combination, a source of fluid under pressure, a pure fluid amplier, a mouthpiece and conduit means interconecing said source, said pure iuid amplicr and said mouthpiece, said pure iiuid amplifier including a body having a power nozzle, V-shaped passage connected thereto by an inner action region, the first leg of said V-shaped passage connected to said monthpiece, rst passage means including a first control port angularly disposed relative to the inner action region lfor leading uid thereto from one leg of said V-shaped passage for switching the uid issuing from said power nozzle from one leg to the 'other leg of said V-shaped passage, second passage means including a second control port angularly disposed relative to said inner action region leading uid thereto from the other leg for switching the Huid issuing from said power nozzle :from said other leg to said one leg of said V-shaped passage, third passage means in said body interconnecting ambient and said second control port, adjustable valve means disposed in said rst, second and third passage means, and ejector pumping means for inducing additional flow to the monthpiece and increasing the rate of discharge from the mouthpiece, said ejector pump means including a casing meniber mounted adjacent the end of said body and having a bore registering with said rst leg, said bore ilaring into a wider diameter discharge end, ports at the narrow diam* eter communicating with ambient, valve means for meten ing ambient air to said port, and passage means interconnecting said bore, ambient and the other leg of said V-shaped passage.

References 'lited UNITED STATES PATENTS 3,030,979 4/1962 Reilly 137--815 3,068,856 12/1962 Bird et al iBS-145.5 3,193,214 8/1965 Lorenz l37--3l.5 3,244,189 4/1966 Bailey 137-815 3,280,832 10/1966 Burns 137--815 3,292,623 12/1966 Warren 137-815 FOREIGN PATENTS 709,848 6/1954 Great Britain.

RCHARD A. GAUDET, Primary Examiner.

K. L. HOWELL, Assisrant Examiner. 

